This is the second approach to this I’ve seen in the last couple months, the other employs a shoulder strap across the top bar which might be easier for heavier bikes. This alternative approach might make the bike less unwieldy though. In either case, I can see the DIYers chomping at the bit to make their own variations.

The Frame Handle (a.k.a. “The Little Lifter”!) is a comfortable, stylish, sturdy, and easy-to-use leather handle for carrying your bicycle, whether it’s up the stairs, across the tracks, or into the metro. Designed for urban commuters, this minimalist handle makes carrying your bike actually feel easier and lighter by lowering the center of gravity and using your normal muscle groups for lifting and holding your bicycle, same as lifting a grocery bag or carrying a briefcase. Because it’s easier to lift and hold, you’re in more control of your bicycle, making it safer to hold in crowded settings.
Without the Frame Handle, most riders either hoist the bike triangle uncomfortably on their shoulder or pick up their bike by the top tube, which requires you to bend your elbow at an uncomfortable angle. This causes stress and strain on your elbow and shoulder and makes carrying your bike feel harder than it needs to be. The Frame Handle has two adjustable buckles that wrap around the down tube and seat tube. It can be mounted above the derailleur and below most water bottle cages. Via Kickstarter